A mud purification and recovery device used for non-open-cut directional drilling;

It is pointed out that the column of whirlpool gaseity in the center has a marked effect on mud purification.

This article analyses the typical disposing method of waste drilling mud in foundationengineering,and narrates the tentative idea of GNJ-2A mud purifier,Shale shaker and cycloneare used to compose a three-step concentrative purification circulation system on GNJ-2Amud purifier,and direct circulalion and reverse circulation mud purification lechnological pro-cess are properly designed.

shale shaker and cyclone are used used to compose a three-step concentrative purification sys-tem on GNJ-2A mud purifier,direct circulation and reverse circulation mud purification technological process are properly designed.

Five-stage-purification is adopted in mud purification system on design to ensure mud performance,thus to meet the increased drilling rate and other requirement.

ZX 200 advanced mud cleaning device with high technique performances is designed for dealing with artificial drilling fluid in constructing diaphragm wall or drilled piles The principles features of and layout it in the field are discussed in this pape

Experimental study on thermal dilation coefficient (TDC) of cement paste at early-age;

Research on retarding mechanism of calcium lignosulfonate to cement paste;

A method to evaluate rheological behavior of cement paste with high fluidity and low water-cement ratio;